The memory sends Carroll into shivers of disgust. She lights her fifth cigarette of the morning.

"Just look," she says, displaying a forearm pocked with scabs and fresh scars. "Look! I had worms inside me."

Hookworms, to be exact. Burrowing, biting, bloodsucking little bastards. Under magnification, they look like the thing that burst out of that guy's stomach in Alien, fangs and all. Once a hookworm invades a host body, it chews its way to the intestinal tract, where it can live for up to 15 years, munching gut tissue for nourishment. The World Health Organization estimates 700 million people carry hookworm, and 50,000 of them die each year (a badly infested host can lose a pint of blood a day). The vast majority of hookworm cases occur in developing countries, since the parasite thrives on poverty.

This offers no consolation to Carroll. Neither does knowing she almost certainly had canine hookworm, not human hookworm.

The hookworms "thought I was a dog," she says, sounding insulted.

The hookworm is a species-hopper. Hookworms carried by dogs, cats or other animals can invade humans who come into bare-flesh contact with infested animal feces.

The good news for humans infested with animal hookworms is that animal hookworms have a hard time burrowing into the guts of a human. Most of them never make it to the intestinal tract. The invaders starve to death.

The bad news is they die slowly, and they die inside you.

Animal hookworms can live for several weeks in a human body, during which time they slither aimlessly, just beneath the skin, moving a few inches per day. The hookworms leave a serpentine trail of infection in their wake, and when they finally die, they break the skin's surface, causing a circular, bloody lesion.

The medical term for this condition is "creeping eruption."

Carroll's boyfriend calls it "more like a plague from God."

"Having worms is weird," says Jim Nelms, 47, who was also infested. "It plays tricks on your mind. It gets so bad, you have to keep from hacking at yourself with a knife, trying to get them out."

Carroll and Nelms still aren't sure how this pox fell upon the house they share in a neighborhood near Desert Sky Pavilion. The couple's hobby is rock collecting, and they say they went camping several times in the weeks leading up to their simultaneous, mid-July outbreak.

"We camped beneath some bats up near Payson," says Carroll. "Maybe that was it."

Maybe. More likely, the source was the home garden Carroll and Nelms planted in their backyard in June. They say they mixed several bags of manure into the newly turned earth as fertilizer, then tended this patch of dirt and manure daily, with their bare hands, often wearing no shoes.

If there were hookworm larvae in the manure Carroll and Nelms purchased (as with a case in West Virginia four years ago), or if an infested neighborhood pet defecated in their produce patch, the couple's backyard garden became a minefield of creeping eruption.

Adult hookworms lay 1,000 eggs a day in their host's intestines. These eggs are excreted in the host's feces. Then, if the open-air environment is suitable (hookworms like it warm, wet and shady), the eggs will hatch into hookworm larvae and lie in wait for contact. When it comes, they latch on and start chewing.

The first symptom of creeping eruption is a burning rash, usually on the forearms and lower legs. When it hit Carroll and Nelms, they went to see a dermatologist, who diagnosed the rash as scabies (a tiny parasitic mite) and treated them with injections of cortisone, a steroid that is ineffective against hookworms.

"The cortisone just seemed to make them go apeshit," says Nelms.

Creeping eruption, like all forms of human hookworm infestation, is rare in the United States, and therefore often misdiagnosed. A 1993 study published in the American Journal of Tropical Medicine reported that two-thirds of creeping eruption patients treated by tropical medicine specialists in the U.S. (most of them travelers who had gone beachcombing barefoot) were misdiagnosed by at least one conventional dermatologist before receiving the correct treatment.

Carroll and Nelms say they were misdiagnosed by four in three weeks. Sifting through a jumbled stack of medical records and insurance bills she stores in a Tupperware bowl, Carroll pulls forth the evidence of each visit.

"This one said it was scabies," she says. "This one said it was a nervous rash. This one asked us if we were burning one another with cigarettes, and this one wanted to treat us with a drug they use for Tourette's Syndrome."

The couple grew panicked as the rash congealed into distinct, red, worm-shaped lines that traversed their bodies. A few worms migrated up Carroll's arms to the skin beneath her face. She stopped leaving the house except to see doctors.

"We were really starting to feel like freaks," she says.

In early August, the first wave of hookworms inside Carroll and Nelms began to die and break the skin, creating open sores.

"They were little gray, hard, L-shaped things," says Carroll. "They'd break apart when you tried to grab them with tweezers."

Horrified and desperate, the couple went to the emergency room at Maryvale Samaritan Hospital.

The staff of the emergency room at Maryvale Samaritan is not unaccustomed to horrified, desperate people walking through the door, arms and legs covered in sores, claiming to be infested with bugs. Crack cocaine or methamphetamine abuse often cause the abuser to feel as if there are insects beneath his skin, leading him to relentlessly pick open his flesh, trying to get at the bugs.

Into this context came Carroll and Nelms, crazy-eyed with fear, gaunt-faced from not eating much for several weeks (creeping eruption causes nausea and diarrhea), with open sores on their limbs and torsos, ranting about worms crawling beneath their skin, and how no other doctors would help them.

"They looked us over and started saying, 'How long have you been awake? What are you on?'" says Nelms. "I told them we weren't on anything, and they said, 'You have to help us before we can help you.' Then I started yelling, 'You can help us by getting these things out of me!'"

The situation did not improve when Nelms opened a knife and prepared to pry a hookworm corpse out of his arm. "I was escorted out by security," he says.

Carroll, a retired Air Force nurse, says she became so hysterical she was given a psychotropic drug she believes was Thorazine.

"They told me it would help me, but it just made me loopy," she says. "I didn't care about anything for a while, and then when I did, I found my clothes and snuck out."

Shortly after the ill-fated emergency room visit, new worm trails began appearing. Carroll and Nelms say they had more than 50 worm trails or lesions each, and believed they had fallen prey to a second infestation -- of what, they still did not know. They were fighting blind, and not well. Carroll had begun cleaning the house obsessively, and shampooed their shag carpeting every three days. This unwittingly created the perfect, damp environment for hookworm larvae tracked into the house from the garden by Carroll, Nelms, or their Afghan hound, which they had shaved (the dog was also infested).

At one point, the couple went to PETsMART and bought a container of Iramectin paste, a de-wormer used primarily by horse breeders.

"We knew we had some kind of worm because you could see the damn things," says Nelms. "So we put some of the horse stuff in water and rubbed it on our skin, and that seemed to knock 'em back a bit."

One frantic day, the couple took turns blasting each other with water from a high pressure hose in a car-wash stall.

"I sprayed so much insecticide in this place I thought I was going to have a seizure," says Nelms. "We didn't know what we were supposed to do, so we did everything we could think of."

Eventually, that included walking to the closest medical facility, no matter how modest. Three blocks away from the couple's house is a NextCare 24-hour emergency center, where Carroll and Nelms were seen by a Russian physician who was substituting at the clinic for a few days.

"We finally got lucky," says Nelms.

The Russian doctor looked over their lesions, then asked to see the soles of their feet.

"No one had asked that before," says Carroll.

In cases of creeping eruption, the big toe and soles of the victim's feet are usually red and swollen from toxins left behind by invading hookworms.

"She took one look at our feet and said, 'You have parasites,'" says Carroll. "She knew what it was, right off, and she got us the right medicine."

The doctor prescribed Thiabendazole, the standard treatment for any hookworm infestation. Valley pharmacies don't stock Thiabendazole, though, and the couple had to wait another two days for it to be shipped, then another five days for the medicine to kill the final surviving worms.

The NextCare doctor suggested Carroll and Nelms take her findings to dermatologists at the Mayo Clinic in Scottsdale, who took skin scrapings and confirmed the Russian's diagnosis.

The garden outside Carroll's house is gone now, and the carpeting inside is new. So is the linoleum in the kitchen, the furniture in the living room, and the air ducts in the walls.

"We got rid of it all," says Carroll. "I got itchy just looking at the couch. It was a nice sectional, but it had to go."

From one perspective, Carroll and Nelms underwent a nightmarish ordeal, real "eye of newt, tongue of dog" stuff. From another, they're lucky it lasted only as long as it did. Severe cases of creeping eruption can last more than six months. The worst case on record in the United States is that of a New York man who sunbathed nude on a beach in Rio de Janeiro and came home with an infestation that took 55 weeks to get under control.

Carroll and Nelms still take daily doses of Thiabendazole (relapses are common in creeping eruption cases where patients prematurely stop taking their medicine), and though they say they still have less energy than normal, it's nothing compared to the utter lethargy and depression that hammered them at the height of their infestation.

Their Afghan hound is getting better, too.

Absent-mindedly scratching at a scab on her leg, Carroll lights another smoke.

"I thought it would be good to talk about this and get it off my chest," she says. "And I guess it is, but it's giving me the creeps. I mean, you really have no idea how creepy worms are until you get some in you."